Honda-SOHC
SOHC.co.uk Forums => CB350/400 => Topic started by: AndyD on July 23, 2020, 08:17:06 PM
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Not sure if of use to anyone but DSS have got some of the 400 silencers back in stock.
I'd stuck a cheap universal one on while waiting for something better to turn up and had an email from them today so hopefully will come through and fit / look better than the current one.
Cheers
Andy
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I bought a full exhaust set from DSS which would have included one of these. I 'had' to return the silencer for a new one as it came dented, but DSS were quick to replace it.
Something to watch out for is the collector to silencer gasket wouldn't fit the silencer, and I ham fisted it and destroyed the gasket. Perhaps there's a trick to skimming them down?
I also had trouble fitting the mounting bracket - it fit loosely, but the silencer didn't align with the bracket. I'm not sure I got it right. The bracket won't fit on in the gap on the top side of the silencer, so this was the only way I could see to fit it.
(https://i.imgur.com/mLsMWDz.jpg?1)
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Yes, can't say I was too impressed either.
Silencer arrived and is a nice finish but also had a couple of issues with it...
Same problem with the gasket - after a 10 minute session of self-doubt determined that it was simply too thick so had to thin the gasket down (messy) to get it in.
The bracket aligned OK but the first bolt stuck in the captive nut and just wouldn't move in or out - ended up shearing the bolt to get the silencer off again!
Turns out both nuts have weld spatter inside about two-thirds of the way into the thread!
I know I should have tried the bolts in the fixings first but really didn't expect that problem on a brand new part.
At least I can fix these issues easily enough but quite annoying and poor quality control somewhere along the line.
Still, silencer does look an awful lot better than the cheap universal one it replaced.
Cheers,
Andy
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Glad to know I wasn't the only one who had some trouble with it.
Instead of buying a new gasket, I ended up getting some high temperature tape which I'll use to build up a perfectly sized shim.
I'm interested in what your bracket looks like, and how it fit into the silencer. There's still a good chance I've just oriented one or the other incorrectly.
Definitely agree though, it looks much better than what I had on before too... a 'shorty megaphone' from ebay.
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Reading this with interest - last winter I purchased a "scratch and dent" silencer and gasket from DS - at a discount - to replace my OEM rusted-out disaster. The couple of small dents won't really be visible. I haven't tried to fit it yet, as the headers are off the bike, but I may try an off-the-bike test fitting of the headers, gasket and silencer to see what's what. I'll also examine all the fittings carefully...
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Hard to see or get good images of the silencer fitting.
Couple of photos hopefully show how it seemed to fit best - but one bolt missing and the other not tight due to the weld in the threads.
Guess the bolts will pull the silencer bracket tighter / better aligned to the frame bracket but the holes all lined up correctly this way and silencer alignment looks right so hopefully this is fitted as intended!
Will take it off, clear out the threads and fit properly when I get a moment.
[attachimg=1][attach=2][attach=1]
Cheers,
Andy
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It's almost hard to tell what we're seeing, everything is so shiny! 8)
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Thanks for that Andy.
My bracket is a separate piece which bolts onto the frame, but the bolts to the silencer on both our bikes look like they're sticking out at a jaunty angle. I think I might just live with it, and use some loctite to try and ensure they don't come undone.
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Yes, can't say I was too impressed either.
Silencer arrived and is a nice finish but also had a couple of issues with it...
Same problem with the gasket - after a 10 minute session of self-doubt determined that it was simply too thick so had to thin the gasket down (messy) to get it in.
Getting ready to install my exhaust - I checked and found the same problem with my silencer and gasket. The gasket’s outer diameter is 49mm, but the diameter of the silencer opening (where the tabs end) is only about 47mm.
Andy, what did you do to thin down the gasket?
I suppose I could bend the tabs open enough to fit the silencer onto the gasket, but it wouldn't slide all the way home that way...
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Matt,
I looked at opening the tabs but decided this was likely to crease and maybe damage the chrome as hard to do neatly.
It also seemed that the problem is the gasket rather than the silencer so I just ‘peeled’ a bit off the outside of the gasket with a Stanley knife, trying to keep it as even / round as possible.
Messy but seems to have worked OK
Good luck with your one
Cheers
Andy
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Matt,
I looked at opening the tabs but decided this was likely to crease and maybe damage the chrome as hard to do neatly.
It also seemed that the problem is the gasket rather than the silencer so I just ‘peeled’ a bit off the outside of the gasket with a Stanley knife, trying to keep it as even / round as possible.
Messy but seems to have worked OK
Good luck with your one
Cheers
Andy
Thanks Andy - I'll check it out!
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I checked out my silencer's captive mounting nuts - one is clear, but one binds the bolt as I thread it on by hand. So perhaps it also has some weld spatter in the threads. I don't have a tap to clear the threads, but careful threading of the bolt may be enough to clear it.
I emailed DSS here in the USA about the gasket - their reply:
Sorry for the issue with the gasket received. Yes this is something we are fully aware of. If you pull out very slightly the slits in the muffler so the gasket fits in, once this has been done you should now be able to a make a perfect seal.
Hmm... they're "aware" of the issue - but their answer appears to be just bend the tabs open and jam everything together.
My recollection of the gasket material that came off the collector tells me that this new gasket is longer than the original - I think I'll gather all my components and lay them out to see how to make it work - it might be difficult to use the old parts for comparison, as I had to basically destroy the old silencer to remove it...
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Matt,
Trying to open up the slits sounds easy but I had a brief look at doing this but backed off thinking the risk of cosmetic damage was too high compared to shaving the gasket down.
I'll be interested to see how you get on whichever way - shame they couldn't just get the gasket thickness right in the first place!
Be careful with the weld spatter - one bolt got completely stuck on mine and sheared off so hopefully you can clear the thread OK.
Sad thing is these should be the 'fun' and easy bits - fitting brand new parts!
Cheers,
Andy
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Thanks Andy! I'll definitely report back!
The bolt (P/N 95700-08016) is an 8x16 flange bolt - I assume it's the "regular" 1.25mm thread pitch and not the "fine" 1mm thread pitch? I wish part number search results would offer thread pitch info and not just diameter and length...
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Interesting that the "tabs" on the repro silencer's collector end aren't as long as on the Honda's.
The DSS version, with slots cut in only about 7/8" from the end:
(https://www.davidsilverspares.com/graphics/parts/18310377017P_3_large.jpg)
And my old Honda one, with slots almost 1/4" longer:
[attachimg=1]
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These are pattern parts and therefore the devil's own work. Why these manufacturers can't try the products on an actual bike and rectify the faults heaven only knows. Been doing the pattern part struggle myself for the last week.
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Have any of you spoken to DSS about this? They pride themselves on the quality of their repro parts and what you’ve been saying clearly dents this image.
I would have thought it’s be in their interest to fix the problem by getting their supplier to Make the part properly, and giving you guys a replacement replacement.
I was considering this part, but don’t think I will now.
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Have any of you spoken to DSS about this? They pride themselves on the quality of their repro parts and what you’ve been saying clearly dents this image.
I would have thought it’s be in their interest to fix the problem by getting their supplier to Make the part properly, and giving you guys a replacement replacement.
I was considering this part, but don’t think I will now.
Yes. Go back one page and read my post #11 - it includes the entirety of DSS's emailed response...
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To be honest DSS is very often just a reseller of these parts most of which are CMS items so they have no real control of the quality.
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FWIW - after cleaning up the welded nuts with a tap, I just did a test fit of the silencer on the bike mounting bracket. It fits perfectly, with no crooked fastener issues. I don't have the header install yet, though - that may change things..
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Think I may have the thread issue with my recently bought DSS silencer as well. Can you confirm the tap size Mattsz?. Also is the conclusion the issue with the gasket is due to the silencer dimensions or the the gasket size? TIA.
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Think I may have the thread issue with my recently bought DSS silencer as well. Can you confirm the tap size Mattsz?. Also is the conclusion the issue with the gasket is due to the silencer dimensions or the the gasket size? TIA.
8mm, 1.25mm pitch for the tap. My original mounting bolts had some rusty threads, so I cleaned them up with a die as well. Smooth results!
I plan to reassemble the exhaust later today (still early morning here!). I'll let you know what happens, but I don't expect to be able to answer your question, since I don't have an original gasket to compare with, and I had to destroy my original Honda silencer's end to remove it from the header, so I can't compare silencers, either...
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So I believe the issue is with the silencer - the opening is too small. I compared the new gasket to a well-used on still mounted on my "spare" collector, and they seem to be virtually the same inner and outer diameter - however the new gasket is about 2mm longer (measuring the cylinder length). The new silencer opening is too tight to fit the new gasket, and too tight to fit on the old one.
I decided to try opening the silencer tabs just enough to work the new gasket in and then try to use the tabs to turn the gasket down to size. It sort of worked, it might need some fine tuning with some sort of blade or scraper...
EDIT: damn upside down thumbnails! I give up...
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Matt,
Glad you got the gasket to 'work' OK.
Finally had a chance to finish off fitting mine today - tidied up the threads and had to lengthen the fixing hole in the frame a small amount but now all fits properly and tight to the bracket etc.
On to the next challenge...
Cheers,
Andy
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It's possible to reduce the outer diameter of the new gasket so that it fits in the silencer better.
I done it on my F1 because I didn't want to wait for the proper gasket coming in the post all the way to CZ.
Here's my botch method,
Find a socket that's a good tight fit into the gasket.
Fit the socket onto an extension piece and clamp it in a vice with the socket base flush to the vice jaws.
Fit the gasket over the socket.
Line the inside of a piston ring clamp (or whatever you have suitable) with 40 grit paper and gently turn the outside of your gasket down to the correct fit.
Hope this helps
Skoti.